A Liquid Crystal Display (LCD) displays images using optical variations caused by injecting and arranging liquid crystal display elements between two glass plates and then applying a voltage to change the arrangement of the liquid crystal display elements. In an LCD, a current image can overlap a previous image due to a slow response time causing blurring. For example, one frame typically has a duration of approximately 16.7 ms when display refresh is 60 Hz. When a voltage is applied to both ends of a liquid crystal material, a physical torque is generated which begins to re-orient the liquid crystal material. The more torque (voltage) the quicker the liquid crystal material responds and the further it moves. By modulating the torque applied to the liquid crystal material, the materials response (and hence color changing accuracy) can be improved. Slow pixel response causes the visual effect of blurring.
To improve response speed of an LCD, response time compensation such as dual frame overdrive or multiple frame overdrive can be used. When using dual frame overdrive, a difference between a pixel value of a previous frame for an arbitrary pixel and a pixel value of a current frame for the pixel is obtained, and a sum of a value proportional to the difference and the pixel value of the current frame is generated. These values can then be used as indices to a LUT (with or without interpolation) to derive the most optimal logic driving value. Multiple frame overdrive operates in a similar manner as dual frame overdrive, but two consecutive previous frames are used rather than a single previous frame. In order to use either overdrive technique, the pixel values of previous frames must be stored in memory.
Accordingly, it is desirable to, among other things, minimize the size of the previous frames stored in memory when using response time compensation in order to improve performance of an LCD.